Why the code execute after redirection

Why the execution goto after redirection using header()

  $flag=1;
  if($flag==1)
      heade开发者_JAVA百科r("Location:page1.php");
  header("Location:page2.php");

when use this code page redirects to page2.php, Why its happen

You need to put an exit; after the header call; PHP does not automatically stop executing code after the client stops loading the page.

The code should be like:-

$flag=1;
if($flag==1) {
    header("Location:page1.php");
    exit();
}
header("Location:page2.php");
exit();

If you don't use the "exit()" / "die()" construct, PHP will continue to execute the next lines. This is because PHP redirects the user to the first-mentioned page (in this case it's "page1.php"), but internally after executing all the statements written in the whole page, even after the "header()" method is executed. To stop this, we need to use either the "exit()" / "die()" constructs.

Hope it helps.

Here is how it works:

Server side: PHP creates a HTML page to send. If $flag == 1, it changes its header to location:page1.php. In every case because there is no else, it then changes the header to location:page2.php.

Then, the page is sent to your brower, which redirects you.

My advice: simply put else before your second header change.

  $flag=1;
  if($flag==1)
  {
      header("Location:page1.php");
      exit();
  }
  header("Location:page2.php");

This should prevent redirection to page2.php. Just remember to put exit() where it's necessary.